Efficiency Of A Multilayer-Laue-Lens With A 102 Mu M Aperture

A multilayer-Laue-lens (MLL) comprised of WSi2/Al layers stacked to a full thickness of 102 mu m was characterized for its diffraction efficiency and dynamical diffraction properties by x-ray measurements made in the far field. The achieved aperture roughly doubles the previous maximum reported aperture for an MLL, thereby doubling the working distance. Negative and positive first orders were found to have 14.2% and 13.0% efficiencies, respectively. A section thickness of 9.6 mu m was determined from Laue-case thickness fringes in the diffraction data. A background gas consisting of 90% Ar and 10% N-2 was used for sputtering. This material system was chosen to reduce grown-in stress as the multilayer is deposited. Although some regions of the full MLL exhibited defects, the presently reported results were obtained for a region devoid of defects. The data compare well to dynamical diffraction calculations with Coupled Wave Theory (CWT) which provided confirmation of the optical constants and densities assumed for the CWT calculations. (C) 2015 AIP Publishing LLC.